Apparatuses for disintegration of straw and similar material

ABSTRACT

A cutting apparatus comprising a rotor on which are mounted discs rotating with the rotor shaft and provided at their periphery with at least one shaft each, said shafts extending in parallel with the rotor shaft and supporting at each end a cutting knife which upon rotation of the rotor pivots in a plane transverse to the axis of said rotor, means being provided on said rotor shaft for enabling the discs mounted thereon to be drawn together axially with the disc hubs arranged end to end in such a manner that said discs will be positioned at a torsional angle relative to one another and the rotor knives be located along a helical line about said rotor.

Gronberg et a1.

APPARATUSES FOR DISINTEGRATION OF STRAW AND SIMILAR MATERIAL Inventors:Sven D. Gronberg, Kvanum; Henry Alf Berti] Gronberg, Falkoping, both ofSweden Gronhergs Gjuteri Och Kvarnfabrik, Rekordverken AB Ottum, Kvanum,Sweden Filed: Nov. 8, 1973 Appl. No.: 413,934

Assignee:

Foreign Application Priority Data Nov. 16, 1972 Sweden 14881/72 US. Cl.241/243, 241/292.1 Int. Cl. B02c 18/18 Field of Search 241/190, 224,238, 243, 24l/292.l

References Cited UNITED STATES PATENTS 5/1941 Treloar ..241/243 10/1960Gronberg 241/243 [451 Apr. 1, 1975 3,186,651 6/1965 Briocini 241/224 X3,380,502 4/1968 Gronberg 241/243 X FOREIGN PATENTS OR APPLICATIONS605,277 9/1960 Canada 241/243 Primary Examiner-Granville Y. Custer, Jr.Assistant Examiner-I-loward N. Goldberg Attorney, Agent, or Firm-Newton,Hopkins & Ormsby [5 7] ABSTRACT A cutting apparatus comprising a rotoron which are mounted discs rotating with the rotor shaft and provided attheir periphery with at least one shaft each, said shafts extending inparallel with the rotor shaft and supporting at each end a cutting knifewhich upon rotation of the rotor pivots in a plane transverse to theaxis of said rotor, means being provided on said rotor shaft forenabling the discs mounted thereon to be drawn together axially with thedisc hubs arranged end to end in such a manner that said discs will bepositioned at a torsional angle relative to one another and the rotorknives be located along a helical line about said rotor.

5 Claims, 6 Drawing Figures r-ATENIED 11% EU 2 OF 3 Fig. 3

PATENTED APR 1 19.75

SHZU 3 0f 3 Fig. 4

APPARATUSES FOR DISINTETRATION OF STRAW AND SIMILARMATERIAL BACKGROUNDOF'THEINVENTION The presentdnvention relates to apparatuses of the kindwhich are, arranged to disintegrate straw and straw like materials andwhich are provided, with a rotor-having several knivespositionedadjacent the rotor periphery and arranged for pivotal motionin a plane'transverse to the rotor axis, said rotor being rotatablymounted in a machine casing having a row of laterally spaced knivesserving as supports or grates to the straw-like material and betweenwhich knives the rotor knives pass to disintegrate the straw. The rotorlikewise comprises a number of discseach one provided adjacent itsperiphery with at least two shafts extending in parallel with the rotoraxis.

In prior art rotors of this kind wherein the rotor knives are positionedradially and are passed through by tie rods which are parallel to therotor shaft and also pass through a number of discs which are mounted onthe shaft so as to be spaced equal distances apart, it is essential thatthe rotor is well balanced as the latter is usually driven at a speedexceeding 3,000 r/min. Spacer sleeves are mounted on the tie rodsbetween neighbouring knives. One has found that if the lengths of thespacer sleeves vary by as little as one tenth of a millimeter, whichoften is the case, and if the number of spacer sleeves in a rotor havinga length of appr. l.5 to 2 meters, exceeds 25, the overall length of arow of rotor knives mountcd'between the two discs positioned at therotor ends may vary by several millimetres. Consequently, when the tierods are tightened, the rotor shaft will be bent to some extent whichresults in unbalanced rotation of the rotor. A further disadvantageinherent in this type of rotors having pass-through tie rods and spacersleeves located between adjacent knives is that exchange of knives thathave broken or need resharpening is a rather complicated andtime-consuming task. As a rule, this work need to be performed in afactory.

. SUMMARY OF THE PRESENT INVENTION One purpose of the present inventionis to remedy the drawbacks outlined in the aforegoing. It ischaracteristic of the invention that the discs incorporated in the rotorhave their hubs positioned end to end on the rotor shaft and are drawntogether axially on the rotor shaft, preferably by means of a tighteningnut, and in that at least one pair of pivotable knives is associatedwith each disc, the inner ends of each pair of knives being engaged onthe opposite ends of adisc shaft projecting throughits disc andextending] parallel to the rotor axis, these discs being positioned atsuch a mutual torsional angle on the rotor shaft that the rotor kniveswill be positioned along a helical line fe xtending about the rotor. I

Because the disc hubs abut against, one another end to end on the rotorshaft the latter is made considerably rigid. For this reason it becomespossible to choose a somewhat-smaller shaft diameter to ,maketheapparatus lighter. There is no risk that the shaft will bendduringassemblyor during operation. As one rotorknife of each pair thereof ispositioned at each endofthe associated disc shaft the latter becomeseyenly loaded.;The

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mounting of the shaft is simple. Preferably, one bearing is positionedat each end of the shaft close to the inner face of the associatedknife, whereby the stresses become insignificant. The highlyunfavourable fan effect which as a rule is experienced in prior artdisintergrating apparatuses is minimized. Owing to the fact that thediscs are mounted in fixed relation on the rotor shaft with the pairs ofrotor knives of adjacent pair of discs circumferentially staggered,there is ample space at the shaft ends for exchange of knives in case ofrupture or breakage without disassembly of the rotor. This position ofthe knives along an imaginary helical line about the rotor circumferencealso has the advantage of improving the disintegration of the straw-likematerial as the operation becomes extremely even. Consequently, one haseliminated the thrusts commonly experienced in the disintegrating workof the apparatus when the knives are positioned in rows in parallel tothe rotor shaft as is normal.

BRIEF DESCRIPTION OF THE DRAWINGS The further characteristics of theinvention and the advantages to be obtained thereby will be describedmore in detail in the following with reference to the accompanyingdrawings, wherein:

FIG. 1 is a vertical cross-sectional view through a cutting apparatus inaccordance with the invention, mounted at the rear end of a combineharvester,

FIG. 2 illustrates on a smallerscale in a side view the rotor and themounting thereof,

FIG. 3 illustrates on an enlarged scale a partly broken cross-sectionalview through the rotor,

FIG. 4 illustrates the rotor in a partly broken longitudinal section,and

FIGS. 5 and 6 are partly broken longitudinal sections showing twovarious embodiments of the rotor discs.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT In FIG. 1, referencenumeral 1 designates the rear end of a thresher mechanism, e.g. thethresher of a combine harvester. The cutting apparatus 2 is intended todisintegrate the straw supplied from the vibrating screen 3 of thethresher l, the straw being cut up into comparatively short pieces. Thecutter 2 comprises both a rotor 4 comprising a rotatably driven shaft 5supporting a number of knives 6 which take part in the shaft rotation,and a support or grate 7 supporting the straw during the disintegrationthereof. The support 7 comprises a row of knives 8 spaced apart adistance of e.g. 50 mm. The rotor knives 6 are arranged, during therotation of the rotor, to pass through the gaps formed between theknives 8. The rotating direction is indicated by an arrow 9. The shaft 5is mounted in bearings 11 in the short sides of abox-like open top andopen bottom machine casing 10 on a pivotally mounted support frame 12 atthe rear end of the thresher mechanism l. The shaft 5 is preferablydriven by means of a belt (not shown) from the thresher mechanism via abelt pulley 13 at one end of the shaft 5. The upper open end of themachine casing 10 is provided with a funnellike section 14 onto whichthe straw is advanced from the vibrating screen 3 and slides downtowards the rotor 4 where the rotor knives 6 engage the straw and cut itinto small pieces against the grate knives 8. At its bottom, the machinecasing 10 is provided with an outlet opening 15 for discharge of the cutstraw pieces.

As evident from the drawings the rotor knives 6 are supported at theirradially inner ends by means of a trunnion 16 (see particularly FIG. 4)in such'a manner that the distance 17 separating these two knives equalsthe distance 18 between two neighbouring grate knives 8. The trunnion ordisc shaft 16, having at both its ends a nut 19, passes through twospacer washers 20 and the inner runner ring 21 of two ball bearings 22as well as spacer sleeve 23 mounted between the bearings. The hubs ofthe respective spacer washer 20 in addition pass through one apertureeach formed in the rotor knives 6. Upon tightening of the nuts 19 therotor knives 6 will be securely clamped such that, together with theshaft 16, the spacer washers 20, the inner runner ring 21 of thebearings 22 and the spacer sleeve 23, they may pivot as a unit in atransverse plane relative to axis of the rotor 4. The bearings 22 aresqueezed into a bore 24 extending in parallel with the rotor shaft 5 ina boss 26 positioned at the outer periphery of a disc 25.

Through the hub 27 of the disc passes the shaft 5 to which the disc hubis secured by means of a locking screw 28. Both ends of the hub 27 arein the form of a toothed wheel serving as a clevis coupling and havingteeth 29 alternating with tooth spaces 30 positioned in such a mannerthat when a number of discs 25 are threaded in a row end to end on therotor shaft 5, the shafts 16 of adjacent discs extend at a definitetorsional angle, eg an angle of 45 (see FIG. 3) relative to one another.Through this arrangement the knife pairs 6 will be positioned along ahelical line extending about the rotor as is diagrammaticallyillustrated by the dashed lines in FIG. 2. The rotor shaft 5 which issupported at its ends by the bearings 11 is provided internally thereofwith two tightening nuts 31, 32 by means of which the entire row ofdiscs 25 may be pressed close together with the hubs 27 in an end-to-endposition. This considerable tightening of the hubs 27 in an axialdirection strengthens the rotor shaft 5 considerably. There is no riskthat the shaft will bend as a result of this tightening operation.Consequently, the rotor constructed as indicated will be well balanced.

In case any one of the rotor knives 6 need be replaced or rcsharpened,one need only loosen the nuts 19 which are easily accessible at theperiphery of the rotor.

ln rotors (see FlG. 5) of the kind where the distance between the rotorknives 6 is to be comparatively small, only one ball bearing 22 isneeded. Otherwise the bearing construction is essentially identical withthe one illustrated in FIG. 4.

Although ball bearings are preferred on account of their advantage inthat such bearings provide excellent lateral guidcncc of the rotorknives 6. slide bearings may also be used. In FIG. 6 is illustrated abearing structure of this kind. ln this case the shaft 16 passes throughtwo bearing sleeves 33, 34 serving as slide bearings and supporting attheir outer ends one rotor knife 6 each between which knives a spacersleeve 35 is mounted. Upon tightening of the nuts 19 the rotor knives 6are clamped against the bearing sleeves 33, 34 and in turn these areclamped against the spacer sleeve 35 in such a manner that all theseparts together with the shaft 16 become movable as one single unit.

The discs 25 are imagined made through diecasting of aluminum or someother suitable metal alloy, such as Silumin. The discs may be arrangedso as to support only one pair of knives 6 but also two diametricallyopposite pairs of rotor knives are possible. In case large rotors areused even three or four pairs of rotor knives, positioned symmetrically,may be used.

The embodiments as illustrated and described are to be regarded asexamples only and the arrangements for supporting the rotor knives 6 aswell as the configuration of these knives may be constructively alteredin a variety of ways within the scope of the appended claims. Othertypes of ball bearings 22 than roller bearings are applicable.Preferably the follower means 29 consist of cylindrical pins extendingin parallel with the rotor shaft 5 and engaging in the end surfaces ofthe hubs 27.

What we claim is:

1. Apparatus for disintegrating straw or like material comprising incombination:

a casing having an upper opening for receiving material to bedisintegrated and a lower opening for discharging disintegratedmaterial;

a row of laterally spaced knives mounted in said casa rotor assemblyjournalled in spaced parallelism to said row of knives within saidcasing. said rotor assembly comprising a rotor shaft, a pluralityofdiscs each having a hub portion and a peripheral portion, the hubportions being hollow and slidably engaged on said rotor shaft andtightening means on at leastone end of said rotor shaft for tensioningthe rotor shaft and compressing said hub portions to integrate saidrotor shaft and discs as a single rotatable unit in which said discs arealigned opposite individual knives of said row of knives, at least onepair of rotor knives disposed in straddling relation to the peripheralportion of each disc so as to extend therefrom and pass in straddlingrelation to that knife of said row of knives with which thecorresponding disc is aligned and mounting means for rotatably anddetachably securing one end of each knife of each pair to thecorresponding disc, and means interlocking adjacent hub portions of saiddiscs so that the pairs of rotor knives thereof are circumferentiallystaggered whereby to provide clearance to allow removal and replacementof individual rotor knives while said rotor shaft and discs remainintegrated as said single rotatable unit; and

means for rotating said rotor assembly.

2. An apparatus in accordance with claim I, wherein said meansinterlocking are cylindrical pins extending in parallel with said rotorshaft and engaging in end faces of said hub portions.

3. Apparatus as defined in claim I wherein said means interlockingadjacent hub portions effects a circumferential angular displacement ofbetween the pairs of rotor knives of adjacent discs.

4. Apparatus as defined in claim I wherein said mounting meanscomprises, for each disc, a disc shaft rotatably carried by theperipheral portion of each disc and having opposite end portionsprojecting therebeyond, the rotor knives of each pair being engaged onthe opposite ends of a corresponding disc shaft and securing nut engagedon each end of each disc shaft to secure said rotor knives in place.

5. Apparatus as defined in claim 4 wherein said means interlockingadjacent hub portions effects a circumferential angular displacement of90 between the pairs of rotor knives of adjacent discs.

1. Apparatus for disintegrating straw or like material comprising incombination: a casing having an upper opening for receiving material tobe disintegrated and a lower opening for discharging disintegratedmaterial; a row of laterally spaced knives mounted in said casing; arotor assembly journalled in spaced parallelism to said row of kniveswithin said casing, said rotor assembly comprising a rotor shaft, aplurality of discs each having a hub portion and a peripheral portion,the hub portions being hollow and slidably engaged on said rotor shaftand tightening means on at least one end of said rotor shaft fortensioning the rotor shaft and compressing said hub portions tointegrate said rotor shaft and discs as a single rotatable unit in whichsaid discs are aligned opposite individual knives of said row of knives,at least one pair of rotor knives disposed in straddling relation to theperipheral portion of each disc so as to extend therefrom and pass instraddling relation to that knife of said row of knives with which thecorresponding disc is aligned and mounting means for rotatably anddetachably securing one end of each knife of each pair to thecorresponding disc, and means interlocking adjacent hub portions of saiddiscs so that the pairs of rotor knives thereof are circumferentiallystaggered whereby to provide clearance to allow removal and replacementof individual rotor knives while said rotor shaft and discs remainintegrated as said single rotatable unit; and means for rotating saidrotor assembly.
 2. An apparatus in accordance with claim 1, wherein saidmeans interlocking are cylindrical pins extending in parallel with saidrotor shaft and engaging in end faces of said hub portions.
 3. Apparatusas defined in claim 1 wherein said means interlocking adjacent hubportions effects a circumferential angular displacement of 90* betweenthe pairs of rotor knives of adjacent discs.
 4. Apparatus as defined inclaim 1 wherein said mounting means comprises, for each disc, a discshaft rotatably carried by the peripheral portion of each disc andhaving opposite end portions projecting therebeyond, the rotor knives ofeach pair being engaged on the opposite ends of a corresponding discshaft and securing nut engaged on each end of each disc shaft to securesaid rotor knives in place.
 5. Apparatus as defined in claim 4 whereinsaid means interlocking adjacent hub portions effects a circumferentialangular displacement of 90* between the pairs of rotor knives ofadjacent discs.